Design of State Space Controllers for Industrial Twin Shaft Gas Turbines
This paper depicts the development of a new control strategy for industrial gas turbines to improve the control accuracy in the entire operating range. In the first step, a complex mathematical model has been developed, which is implemented into the controller dynamic simulation. An automatic operating point dependent linearization process permits the model to be displayed in a linear state space description. Three established controller design procedures have been applied to the process. In the past, only a small number of state space control designs have been presented for industrial gas turbines. These approaches use low order mathematical descriptions, which often do not describe the system behavior in detail. This paper presents a controller design for a more detailed mathematic model of the 15th order. It is indicated, that certain controller designs are difficult to realize or even fail. These effects result from unfavourable numerical conditions (depending on the operating point) in combination with the high order of the approximated linear system description. The tested pole placement designs show favorable closed loop system dynamic behavior and were improved by adding an integrating part to the controller.